This Washington Post poll was conducted by telephone Jan. 9-12, 2014, among a random sample of 1,003 adult residents of the District of Columbia. Interviews were conducted on conventional (500) and cellular phones (503), including 234 interviews with cell phone-only respondents. The poll included interviews with 669 voters registered with the Democratic Party or who plan to register as Democrats before the April 1 primary election, and 394 likely Democratic primary voters. The margin of sampling error for overall results is four percentage points. Sampling, data collection and tabulation by Abt SRBI, Inc of New York, NY.
Sample size and margin of error for subgroups
Sample size Error margin
All D.C. adults 1,003 4
Registered voters
or plan to register (RV) 849 4.5
Registered Democrats (Dem RV) 669 5
Likely primary voters (LV) 394 6.5